Reduced Movie Resolution on Android VR (Vive Focus Vision)

Hi,

I’ve got a problem with playing a .mp4-movie on my HTC Vive Focus Vision:
The movie is stereo 180° side-by-side with a resolution of 4096x2048. When I package the project for windows and start it on my laptop with the connected headset, everything is fine. But when I package it for android, install on my headset and play it standalone, then the movie seems to have a lower resolution.
I’ve attached two screen shots, where you can see that.

Android:

Windows:

I assume, that unreal does some kind of reduction when packaging for androis, but I cannot find out, where I can deactivate it.

Does anybody know how I can solve that? Or is it another problem, that I don’t see yet?

Thanks for any help